External reference components are often used to calibrate the performance of an individual circuit on an integrated circuit (IC). These components include but are not limited to passive components such as resistors, capacitors, and inductors. These components also include but are not limited to active components such as op-amps, voltage regulators, and current regulators. The number of external reference components used to calibrate individual circuits on an IC add to the cost of producing ICs, components, electrical boards, and computer systems. One method used to reduce the cost of producing ICs is to reduce the number of external reference components used to calibrate or test ICs.
There is a need in the art to reduce the number of components used to calibrate integrated circuits. An embodiment of this invention reduces the number of reference resistors required to calibrate optimal output impedance for off-chip drivers on an IC.